Elorian, thats funny you started with a fluval canister filter and a prizm skimmer...cause I started with an Eheim Professional II and a prizm skimmer. I also like the sump much, much better than the canister filter. It opened a whole new world of options. I was able to move the heater and skimmer down there, giving my tank a much "cleaner" look.
My siphon is a u-tube and no matter how many times I redo it, weeks later I have a big bubble of air on the top of it. I will be moving in a couple years and plan to upgrade to a larger tank...one that I will make sure is pre-drilled!!